Investigation of heavy metal pollution of trees in a contaminated industrial area in the north of Iran

Abstract

Phytoremediation is the technology of purging soils and water systems from heavy pollutant metals. Cadmium is one of the heavy elements, which is environmentally important due to its toxicity to humans and animals. Toxicity and accumulation of cadmium in body organs through eating contaminated food has an important role in endangering human's health. To this end, trees of buttonwood were prepared and irrigated with nutrient solution containing cadmium chloride in 10, 15 and 20 mM for 12 months. Then the root, stem and leaf samples were harvested and the amounts of cadmium element in stem, root and leaf organs together with the growth parameters were measured. This study determined the amount of cadmium accumulated by Platanus occidentalis. Furthermore, the comparison between accumulation and transfer of cadmium in the study showed that absorption of this metal by the root is more than its amount in stem and leaf. The result of this research shows that buttonwood has the potential for cadmium accumulation without any serious damage to its growth. Regarding the extent of contaminated industrial areas, petrochemical industry, power plants and vast contaminated municipal areas, there is a great need for planting fast-growing and tolerant plants like buttonwood.